There has been a wave of arrests in Turkey of individuals allegedly connected to the murder of Andrey Karlov, Russia’s ambassador to Ankara.

According to the Russian news agency TASS 13 people have been taken into police custody, including the assassin’s parents and sister, six other suspects in the west port city of Izmir, and four other people in the assassin’s home province of Aidyn.

It is important to say that none of the individuals arrested has so far been charged or convicted of anything, but the fact that so many people are being arrested suggests that the Turkish authorities do not think the murder was the action of a lone assassin but believe that a conspiracy was involved.

Already certain Turkish officials are alleging that the Gulen movement – which they also blame for the July coup attempt – was behind the murder, and there have been apparently even been some suggestions in Turkey that the trail of the conspiracy leads back to the US – a claim that has provoked a furious denial of US involvement from the Obama administration. US State Department spokesman John Kirby is reported to have said the following

It’s a ludicrous claim, absolutely false, there’s no basis of truth in it whatsoever. Any notion that the United States was in any way supportive of this or behind this or even indirectly involved is absolutely ridiculous.

Turkish Foreign Minister Cavesoglu is however reported to have told US Secretary of State John Kerry of Gulen’s suspected involvement in the assassination, and has supposedly also told Kerry that Russia agrees with the Turkish authorities that Gulen was involved. The Erdogan aligned Daily Sabah reports their conversation in this way

Foreign Minister Mevlüt Çavuşoğlu told his U.S. counterpart John Kerry that both Russia and Turkey are aware of Gülen’s involvement in the assassination of the Russian envoy. The two ministers had a phone call upon Kerry’s request, diplomatic sources said on Tuesday.

The sources said that the top diplomat told Kerry “Both Turkey and Russia know the Gülenist Terror Cult (FETÖ) was behind Russian envoy Andrey Karlov’s assassination.” The ambassador was killed during a speech at an exhibition in Ankara on Monday by a gunman dressed as a guard.

The Erdogan government has a habit of blaming the exiled cleric Fethullah Gulen and his movement for all its problems – including the SU24 shoot-down and the July coup attempt – and early claims in Turkey pointing the finger at Gulen and claiming that Russia agrees with this conclusion should be treated with care. However the vigour with which the investigation is being conducted suggests that the full truth of who if anyone was behind the murder should become known before long.